Welcome to the Microbiology Information

According to the NSW Food Authority and the Sydney South West Area Health Service (SSWAHS) Public Health Unit, there is an outbreak of gastroenteritis involving 98 people, many of whom ate food products from a Homebush hot bread shop over the weekend.

So far eighteen people have been hospitalized, and public health officers are currently interviewing all cases.

In the majority of cases interviewed so far, many reported having eaten either pork rolls or chicken rolls from the a Vietnamese bakery called the French Golden Hot Bread shop in Homebush West, opposite the Flemington train station. So far, thirteen cases have been confirmed as having salmonella infection. Incidentally, food poisoning involving Vietnamese Pork roll has occurred a few times in the past from other similar bakeries around the country.

SSWAHS Public Health Unit warns anyone who may have eaten these food products from the bread shop between Friday 23 March and Tuesday 27 March to be vigilant for the symptoms of salmonella infection and seek medical care.

Common symptoms of salmonella infection include diarrhea, abdominal pain, fever, nausea and vomiting. Symptoms usually last four to seven days.

The NSW Food Authority has advised that it sent inspectors into the bread shop to examine food safety practices and to sample foods for laboratory testing. It has placed a prohibition order on the bread shop restricting it from producing or selling the implicated foods. This basically shuts down the shop.

Dr Leena Gupta, SSWAHS Director of Public Health, recommends that anyone who contracts gastroenteritis should keep up their fluid intake, stay home and not return to work or school until 48 hours after symptoms have stopped.

People suffering symptoms should also not prepare food for others until at least 48 hours after they have completely recovered from the illness.

The cooling towers of an Uluru hotel have tested positive for legionella and may be the source of infection for a European tourist who has legionnaires’ disease.

A spokesman for Voyages Hotels and Resorts, which owns the Desert Gardens Hotel near Uluru, said routine testing of the cooling towers carried out last week returned a positive legionella reading.

The towers were in an area adjacent to the hotel.

“We were advised on Friday that a European male tourist has contracted legionnaires’ disease on a recent visit to Australia,” the spokesman said.

“He stayed in a number of different locations but one was the Desert Gardens Hotel.”

He said that at this stage there was no evidence the two events were linked, but further testing would be done to establish whether the strain found in the cooling towers was the same as that contracted by the tourist.

“We are working with the Department of Health to establish whether we can match the two,” he said.

“We have identified the person’s doctor and are trying to get in contact with that person … to do the matching.”

All staff and visitors to the hotel between February 20 and March 14 this year were being contacted to advise them of the test findings.

The spokesman said staff were more likely to have been exposed to any danger, as the cooling towers were in an area not regularly frequented by guests.

The cooling tower system in question had been closed off and decontaminated, and the hotel was awaiting the results of new tests to give the all clear.

“In the meantime, it’s off limits to all people,” the spokesman said.

He defended the hotel’s maintenance routine, saying testing of cooling towers was not mandatory in the Northern Territory.

“We test ours every month, without fail,” he said.

Source: The Age

Although it has been suspected as being good for your health, probiotics may also protect against food poisoning.

Irish scientists report that a combination of five probiotic strains may reduce food poisoning by salmonella, if results of their pig study can be translated to humans.

“The administered strains of probiotic bacteria improved both the clinical and microbiological outcome of Salmonella infection in pigs,” wrote the researchers, led by Colin Hill from University College Cork. “Unlike the normal Lactobacillus acidophilus or bifidobacterium probiotic bacteria, these strains offer significant benefit for use in the food industry and may have potential in human applications.”

According to the European Commission, salmonella induced food poisoning costs the UK economy alone around €1.5 billion each year, with 160,000 cases reported annually Europe-wide. In addition about 1.4 million Americans are estimated to suffer annually from salmonella, according to the Centers for Disease Control and Prevention.

The new research divided 15 weaned pigs and fed them milk supplemented with a mixture of five Lactobacillus probiotic strains (two strains of Lactobacillus murinus and one strain each of Lactobacillus salivarius sub specie salivarius, Lactobacillus pentosus, and Pediococcus pentosaceous), or placebo (regular milk) for 30 days.

After six days of the probiotics, the pigs were given an oral dose of Salmonella enteritica serovar Typhimurium. The health and microbiology of the faeces were monitored for 23 days.

According to the researchers in the journal Applied and Environmental Microbiology, the pigs receiving probiotics showed reduced incidence, severity and duration of diarrhea. It was also significantly lower in numbers of Salmonella from faecal samples after 15 days post-infection.

The probiotic milk group also gained more weight than the control pigs, they said.

Probiotic products containing ‘friendly’ bacteria are now well accepted by consumers in many European countries, with putative benefits highlighted for gut and immune health.

The benefits for gut health have been reported to be due to the probiotic bacteria adhering to the walls of the intestine, which inhibits the ability of the pathogenic Salmonella to stick and colonise the gut, thereby reducing the infection.

Further research is needed, particularly on whether similar positive results are obtainable in human subjects.

Source: Applied and Environmental Microbiology
Volume 73, Issue 6, Pages 1858-1863
“A five-strain probiotic combination reduces pathogen shedding and alleviates disease signs in pigs challenged with Salmonella enterica serovar Typhimurium.”
Authors: P.G. Casey, G.E. Gardiner, G. Casey, B. Bradshaw, P.G. Lawlor, P.B. Lynch, F.C. Leonard, C. Stanton, R.P. Ross, G.F. Fitzgerald, C. Hill.

Here is an interesting recall. National Foods, an Australian Dairy manufacturer is recalling their cheese under the Tilba Cheese brand because of salmonella detection. The implicated cheese is Tilba Club Cheese, Tilba Trilogy - Vintage, Summer Herbs and Sundried Tomato. 140g Wedge. Plastic (Thermoform) Wrap. Best Before 28 August 2007.

Salmonella testing in cheese is not a requirement by state regulation unless there are ingredients added after pasteurization. In this case it’s the herbs and sundried tomato and I would definitely sue this company if the link proved positive. It looks like National Foods do not have a qualified or experienced microbiologist and this could be regular occurrences considering the recall of their pasteurized milk from E.coli earlier this year.

I think I’ll stick with my favorite cheese, Coon.

Here we go again. Another outbreak of listeria and this time it’s the end user and not a food manufacturer that’s in trouble.
According to the Food Standards Agency (FSA) and Health Protection Agency (HPA), they are alerting consumers to the fact that certain sandwiches may have been contaminated with listeria. The sandwiches were supplied to establishments in London and the South East of England by Kent-based Anchor Catering.

As usual, the Health Protection Agency is not currently aware of any reported cases of listeria infection as a result of people eating these sandwiches as it is still too early. As listeria targets the high risk groups such as the elderly, pregnant women, immuno-comprimised and the young, the vast majority of consumers will not be affected by this incident.

The implicated sandwiches, with a use-by dates from 21 February to 14 March, were supplied to a range of establishments in Kent, Sussex, Essex, Middlesex, Surrey and Greater London including schools, hospitals and local authorities before the problem became known. The majority of the sandwiches were labeled as Anchor products and some others were labeled as Pomegranate.

The problem was identified by Ashford local authority after a very small number of samples tested positive for listeria during routine sampling. The risk of listeria infection from eating these sandwiches is very low but as a precautionary measure, the Agency and HPA are alerting consumers about the possible contamination.

As mentioned earlier vulnerable groups such as the elderly, pregnant women, the young those with lower immune system are more at risk.
Food Standards Agency Chief Scientist Dr Andrew Wadge said: ‘Listeria doesn’t pose a threat to the vast majority of the population but it can be serious for some vulnerable groups such as pregnant women. We are working closely with the company and the local authority to discover how this happened. Evidently it’s poor hygiene.

‘Although the company took prompt action to notify customers and withdraw the product, large numbers of sandwiches may have been consumed before the problem was detected.’

On discovery of contamination, Anchor Catering voluntarily suspended production and has informed the Agency that it contacted the establishments supplied with the sandwiches to withdraw them from sale. The FSA and local authority are working with Anchor Catering to identify the source of the contamination, and production at the factory remains suspended.

Let’s hope they do conduct a thorough environmental investigation of the area, cutting machines, raw ingredients to find the source and put systems in place to control it.

If this happened in the UK, it can happen anywhere in the world. That’s why the world needs more good and expereinced microbiologist!

Did you know that the ability of micro-organisms to survive extreme environmental conditions is partly determined by their capacity to protect DNA from destructive chemical and physical conditions.

Some bacteria form endospores that can resist extreme conditions which include high pressure, extreme heat or cold, drought, starvation, most chemical poisons and UV-radiation. Spores may remain dormant for centuries and may even survive over geological time and through interstellar travel.

One extreme heat resistance micro-organism is the spores of the thermophilic sulphate-reducing bacterium Desulfotomaculum kuznetsovii.

About 10% of the spores of this organism survived a heat treatment at 140 ºC for 15 min., which is unprecedented.

This unusual characteristic is represented by a z-value (thermal inactivation coefficient) of 16.7 ºC. The decimal reduction value at 120 ºC is 4 hours, which is highest one of the highest ever.

Legionella was detected in a New Zealand Hospital in Christchurch. Health officials say the office-type water cooler filter may be the first case of its type in the world.

They are warning businesses to test office water cooler filters after the find.

Microbiological testing was done at the hospital last October after a patient showed symptoms of legionnaire’s disease and one of 14 office-style water coolers was found to have a “significant level” of legionella bacteria in a filter.

Canterbury District Health Board spokeswoman Michele Hider said the bacteria found in the water filter was different to the type that had affected the female patient and the testing had been done as a precaution. There was no evidence to suggest the water cooler was linked to any hospital patients or visitors becoming unwell.

The hospital acted as soon as the results were confirmed by removing the filter. The filter still had some months to go before its expiry date.

Canterbury medical officer of health Mel Brieseman said office water coolers and drinking water filters were not usually checked for legionella because the disease was generally contracted through aerosol spray.

“We believe this is the first case of significant levels of legionella being detected in a drinking water cooler anywhere in the world, so we will be publishing the findings as a scientific curiosity,” he said.

Dr Briesman warned that water filters needed to be changed regularly to prevent a build-up of a variety of bacteria, including legionella.

It was “standard advice” for people to use masks and gloves when handling potting mix to prevent legionellosis.

Small amounts of legionella occurred naturally in all untreated water supplies but could multiply to potentially harmful levels in the right conditions.

However, Dr Brieseman said the risk of ill health from drinking water containing significant amounts of legionella was considered low, compared with inhaling the bacteria as mist or steam.

Source

According to the Sydney Morning Herald, a listeria contamination scare has forced a Victorian food processor to recall its smoked trout mousse products after an elderly Melbourne man became ill.

The 89-year-old victim fell ill after eating the Yumi brand of smoked trout mousse and subsequent tests had proven positive for listeria, Victorian chief health officer Dr Robert Hall said.

The health scare has prompted 200 gram packs of Yumi-branded smoked trout mousse or dip with use-by dates of 10/03/07 to 16/03/07 to be recalled from supermarkets across Victoria and NSW.

“People should not eat this product and should return it to the point of purchase,” Dr Hall said.

“The company is cooperating with the recall and has assisted us in the investigation.”

Authorities say listeria infection is uncommon but can lead to death in the elderly and those whose immune systems are not working properly. It is also a hazard to pregnant women and their unborn babies.

Symptoms, which can take up to 70 days to appear, can include fever, headache and aches and pains and if untreated can lead to meningitis or septicaemia.

The bacteria could be treated with antibiotics and the 89-year-old man taken ill had fully recovered after treatment, Department of Human Services spokesman Bram Alexander said.

Source

Hepatitis A is a food borne virus that is transmitted via the faecal-oral route and infection is passed from person to person via foods and beverages contaminated with faeces or by direct personal contact.

Foods most susceptible include ready to eat foods that does not receive any further heat treatment. They include those eaten without cooking such as fresh produce which may be irrigated with contaminated water (salads), and bivalve shellfish (such as oysters) which may be grown in waters contaminated by human faecal effluent.

Oysters feed by filtering particulate matter such as algae from the surrounding water. They can accumulate viruses and other pathogenic microorganisms if they are present in the water during feeding. Once accumulated, viruses may take weeks to purge from an oyster, long after faecal coliform counts of the harvest waters have declined to permitted levels. The common practice of consuming oysters raw or mildly cooked means contaminating viruses within the oyster will not be inactivated prior to consumption, potentially resulting in food borne infection.

In Australia during 1997 there were more than 400 hepatitis A cases, including one death that was linked to consumption of contaminated oysters harvested from the Wallis Lakes area in NSW.

The source of the virus was probably untreated human sewage effluent which flowed from upstream of the oyster lease areas because of unusually high rainfalls. As a result of this outbreak, NSW adopted the internationally recognized Australian Shellfish Quality Assurance Program (ASQAP). The Program has been highly effective in the control of oyster-borne illness. In May 2006 Food Standards Australia New Zealand’s Primary Production and Processing Standard for Seafood was introduced. The Standard sets out food safety and suitability requirements for seafood generally from pre-harvesting production of the seafood up to, but not including manufacturing operations.

Research funded by the Australian Food Safety Centre of Excellence (AFSCoE) on the effects of High Pressure Processing (HPP) on hepatitis A virus in oysters was completed by a PhD student, Stephen Grove, in 2006.

The non-thermal technique of HPP is currently used in the United States to extend the refrigerated shelf life of oysters by inactivating spoilage microorganisms without altering sensory or nutritional qualities. Pressure is applied to oysters submerged in water within a pressure vessel and varies between 250 and 450 megapascal (MPa). Oysters are also shucked by the process, releasing the adductor muscles that hold the oyster shells tightly closed, enabling easy removal of meat without shell damage. One such company is Goose Point Oysters.

The AFSCoE PhD research investigated the effect of a range of pressure and processing times at different salt concentrations, on the viability of hepatitis A virus in artificially contaminated oyster meat. At a pressure of 450 MPa, a 100 fold reduction of hepatitis A in oyster meat was achieved by a 300 second treatment time. The sensitivity of hepatitis A virus to HPP was increased by lower salt concentrations within the oyster meat. A predictive model of the data was developed, and may be used by oyster processors to predict the inactivation of hepatitis A resulting from a particular treatment.

Here are some interested facts on food related recalls in Australia during 2006. According to the Australian and New Zealand Food Standards site, there were 58 consumer level food recalls in Australia.

Interestingly, the majority of these were due to undeclared allergens such as peanuts or contamination by foreign matter such as metal. Whilst microbial related contamination has been common in the past, only 13 of 58 were attributed in 2006 with Listeria monocytogenes or Salmonella species being the most frequently implicated.

Three recalls were conducted as a result of processing faults, two were due to possible microbial contamination through inadequate or failed processing and the other was due to the presence of an allergen caused by the addition of an incorrect ingredient. Other reasons for recalls involved incorrect or non-permitted use of chemicals or ingredients.

In neighboring New Zealand the most common reason for a food recall in 2006 was the presence of foreign matter (38 percent of 26 recalls), followed by undeclared allergens (23 percent) and microbial contamination (19 percent). Quality issues or chemical contamination were the cause of the remainder of recalls in New Zealand.

Due to the increased mandatory warning statements on labels for products containing specified food allergens, there has been greater consumer awareness of the food allergen issue. This has resulted in a noticeable trend in recall data over recent years with marked increases in the number of recalls due to undeclared allergens. In Australia during 2002 there were 8 food recalls due to the presence of allergens, whilst in 2003 there were 40 with most of these consumer initiated.

Recall data can be used to raise awareness in the food industry about hazards that frequently occur. Food businesses can then take steps to prevent further occurrences through factoring in this information when developing or reviewing food safety programs.